Method of plugging a pipe or bore accessible of one side only

ABSTRACT

Method for plugging up the back end of a pipe or bore exclusively accessible via its front end with the aid of a tubular body brought into the pipe or bore and expanded against its wall by means of a pulling device with a mandrel, previously inserted in the tubular body, the wall thickness of which has been minimised to such an extent at one end as to take up the active part of the mandrel, the tubular end concerned being sealed by a cap or the like.

United States Patent Meijers 1 1 Oct. 2, 1973 [54] METHOD OF PLUGGING APIPE 0R BORE 2,821,323 1/1958 Lee 29/523 UX ACCESSIBLE OF ONE SIDE ONLY3,119,177 H1964 Knechl. 138/8) X 3,451,583 6/1969 Lcc r r t 1 .1 138/89X [75] Inven r: J h n E- M j Gravenhage. 3,525,365 8/1970 Meulcndyk 13889 Netherlands FOREIGN PATENTS OR APPLICATIONS 1731 Ass'gnec Nera'wmTheHague 538,132 11/1931 Germany 138 89 Netherlands [22] Filed: Mar- 10,1972 Primary ExaminerCharlie T. Moon [2]] App No 233 764 Att0rneyNelsonLittell, Jr.

Related [1.8. Application Data I 57] ABSTRACT [63] Continuation of Ser.No. 832,152, June 11, 1969,

abandoned Method for plugging up the back end of a p1pe or boreexclusively accessible via its front end with the aid of 521 vs. c129/523, 85/70, 138/89 a tubular y brought into the P or bore and 51 lm.c1 821d 39/00, B23p 11/02 Panded against its Wall by means of a p gdevice [58 1 Field of Search 29/1574, 401, 523; with a mandrel,Previously inserted in the tubular body, 13 9 90; 35 70 the wallthickness of which has been minimised to such an extent at one end as totake up the active part of the [5'6] References Cited mandrel, thetubular end concerned being sealed by a UNITED STATES PATENTS caP the1,994,210 3/1935 Shobert 29/523 X 1 Claim, 3 Drawing Figures INVENTOR.

JOHANNES E.v MEI'IERS METHOD OF PLUGGING A PIPE OR BORE ACCESSIBLE OFONE SIDE ONLY This is a continuation of Ser. No. 832,152 filed June II,1969 now abandoned.

The invention relates to a method for plugging up the back end of anelongated opening such as a pipe or bore exclusively accessible via itsfront end, a mandrel attached to the end of a draw-in-rod being pulledinto a tubular body provided locally in the pipe or bore with the aid ofa pulling device, as well as a device for carrying out the method.

Such methods are known in the art and have the drawback that the mandrelto be drawn into the tubular body, itself serves as a sealing plug inco-operation with the tubular body and consequently remains behind inthe latter. This necessitates for the devices special provisions todetach or to sever the pulling device and the draw-in-rod from thepulling-up devices stated.

Further such sealing plugs are inadequate safeguards against leakage,which may be especially hazardous if it concerns a pipe or bore in aheat exchanger operating with a radioactive medium.

In the method according to the invention the above drawbacks are absentbecause the tubular body itself serves as the plugging-up device, as itis expanded in the pipe or bore to be plugged.

Therefore the method according to the invention is characterized in thatthe tubular body, with a mandrel previously inserted into it, is sealedat the back end, subsequently is locally brought into a pipe or bore andfinally is expanded against the inner wall of the pipe or bore bypulling the mandrel through the entire length of the tubular body andthus removing it.

The device for carrying out the method is very simple because of alldevices to be brought into a pipe or a bore only the tubular bodyremains behind.

Not only can the pulling device and the draw-in-rod be re-used severaltimes, also the more or less complicated detachable and/or severablejoints have been dispensed with.

The device according to the invention is characterized in that itcomprises a tubular body, the wall thickness of which has been minimisedto such an extent at one end along a sufficient distance that into thespace concerned the active part of a mandrel can be just taken up andthe tubular end provided with the active part of the mandrel, isprovided with a sealing, such as a bottom, cap or the like.

When the tubulur body with the sealed end facing forward is locallybrought into a pipe or bore with the aid of a pulling device, only themandrel already present in the tubular body need to be pulled entirelythrough that part of the tubular body not minimised in wall-thickness inorder to expand the mandrel against the inner wall of the pipe or bore.

When applying a metal plugging-up device in a metal pipe or bore as anextra provision the tubular body may be remotely welded from the insidelocally to the inner wall of the plugged-up pipe or bore in ways such asknown in the art.

Hereinafter the invention will further be elucidated with reference tothe drawing, in which by way of example an embodiment is given.

In it:

FIG. 1 shows a cross-section through a plugging-up device with mandreland pulling-device, provided together in a pipe;

FIG. 2 a cross-section through a plugging-up device expanded in a pipeend;

FIG. 3 a cross-section through a plugging-up device expanded in a borein a tube-sheet of a heat exchanger designed for operating with a liquidmetal.

In FIG. 1 by l a pipe is indicated, in which a pluggingup device 2 withmandrel 3 has been pushed to the end of pipe 1 with the aid of a presssleeve 4. The correct position of plugging-up device 2 in the pipe endis determined by the length of press sleeve 4 provided with a socket 5.The wall thickness of plugging-up device 2 is minimised along a shortdistance 6, so that a space is formed in which the active part ofmandrel 3, which is just fitting in this space, is taken up. Thereafterthis space is sealed by a small cap 7 welded on to it.

When mandrel 3 is pulled entirely through and out of plugging-up device2, with the aid of a well-known pulling-device that is not shown in thedrawing and that rests on socket 5 of press sleeve 4, the non-minimizedwall is milled tight against the inner wall of pipe 1.

In FIG. 2 an example is given of a plugging-up device 2 milled tight ina pipe end.

Mandrel 3 has entirely been pulled through pluggingup device 2 andthereafter removed out of pipe 1 together with press sleeve 4.

In FIG. 3 a detail is given of a tube-sheet of a heatexchanger designedfor operating with a liquid metal, in which pipe 8 is welded againsttube-sheet 9 immediately at its entrance into the latter.

According to the manner described above pluggingup device 2 has beenbrought from the front end through pipe 8 into bore 10 of pipe wall 9and expanded in the latter. As an extra provision a weld connection 11has been provided between plugging-up device 2 and bore 10 by remotelywelding in a way as known per se in the art from the inner wall ofpluggingup device 2 with the aid of automatic welding equipment withoutaddition of welding material.

I claim:

1. A method for plugging the back endof an elongated opening such as apipe or bore exclusively accessible by its front end which comprises thesteps of pushing a one-piece cylindrical plug-up device of substantiallythe same diameter as said elongated opening and sealed at one end, saidplug-up device having a decreased wall thickness adjacent said seal anda mandrel therein having a bulged head just fitting said decreased wallthickness, into and through said elongated opening to the point wheresaid seal and at least part of said decreased wall thickness of saidplug-up device extend at least to the back end of said elongated pipeand withdrawing said mandrel out the front end of said elongated openingwhile maintaining said plug-up device stationary in said elongatedopening whereby the walls of said plug-up'device are expanded.

, At testing Office):

- {UNITED sings ATENT OFFICE 1 v ERTIFICATBQF CURRECTION "Patj gm; 1 124 4 I mated cf 1973 v v I Johannes Meijcrs I Q It is 'fiertified thaterror appears in the above-identified patent. and that :said-Iettez sPatent al e hereby corrected as shown below Heading Y'Assighee 2" N, V.N eratc aom" shou ld read Assigne: B.- V. Ner eitoom in headin g aftrAppln.

N c ."233 ,-7 6 4-inse irt C1aim$, Priorityappliation Ngtherl a nici s;Ju n e 2 7 1968', N0 68.09056 Signed a d sealed this 1ST: daypf October1974.

(SEAL) At test McCOY I I. GIBSON JR. 7 v C. MARSHALL DANN V jCommissioner of Patents uscoMM-Dc come-i 69 ORM Po-1osb( 1o-e9) f i I Iv i v I I 7l- U5. GOVIRNMENY PRYNYING OFFICE: I o

1. A method for plugging the back end of an elongated opening such as apipe or bore exclusively accessible by its front end which comprises thesteps of pushing a one-piece cylindrical plug-up device of substantiallythe same diameter as said elongated opening and sealed at one end, saidplug-up device having a decreased wall thickness adjacent said seal anda mandrel therein having a bulged head just fitting said decreased wallthickness, into and through said elongated opening to the point wheresaid seal and at least part of said decreased wall thickness of saidplug-up device extend at least to the back end of said elongated pipeand withdrawing said mandrel out the front end of said elongated openingwhile maintaining said plug-up device stationary in said elongatedopening whereby the walls of said plug-up device are expanded.